Thomas Froman wrote:
I think that is close. In the excellent book Aikido Shugyo, even though no clear definition is given Shugyo is explained as " 'ascetic training' , constant training in order to unite body, mind and heart." I hope that helps.
Basically, it means any kind of intensive study or training. I believe that the word has it's roots in Buddhist ascetic training, but today it's used for everything from Budo training to studying for the Junior High school entrance exams.